Display devices containing fluids which can be switched between different fluid configurations to provide different optical characteristics are known. Several measures have been proposed to control the motion of the fluids within a picture element of the display device.
In a known display device, a movement of the fluids during switching is controlled by using an insulating layer on the first support plate having a particular shape to modify an electric field applied to the fluids. A special electrode structure or an inhomogeneous oil fluid layer may be used alternatively to control the fluid motion.
Another known device has picture elements which have a shape that determines, upon switching, a preferred direction of movement of fluids within the picture elements.
An optical switch containing fluids in which the shape of an electrode used to apply the voltage determines a preferred direction of movement of the fluids upon switching is known.
A known display device has a protruding hydrophilic part on an otherwise flat first support plate. The hydrophilic part operates as oil movement initiator. The arrangement of the protruding part requires an additional process step during the manufacture of this display.
It is desirable to provide a display device in which the control of the fluid motion can be made in a simpler manner.